Hi Jay,
In my opinion, you can not change the production start date from 00:00 to 07:00. may be other group members have better idea.
when you see detailed scheduling, it will show the start time as 07:00 for work center, but for the plan order start time would show the 00:00.
if you are using it for report than you can use the data from KBED.
otherwise use userexit for it.
regards,
Solomon